Does a transplant before dialysis have to be from a live donor?
No, but almost all transplants before dialysis are from live donors. This is because kidneys from deceased donors (people who have died and their family donates their organs) get handed out in this region (UNOS Region 1, which includes Massachusetts, Maine, New Hampshire, and parts of Connecticut and Vermont) by a number of considerations, but wait time on the transplant list is one of the most important.
You cannot start gaining time on the transplant list in Region 1 until you actually start on dialysis. Prior to starting dialysis, you can get a transplant if you are active on the transplant list and someone becomes a donor who just happens to match you on all the proteins important for rejection (perfect match donor).
While this is possible, it is not something you can count on happening. So having a live donor is the most common and best way to get transplanted before starting dialysis.